1Assistant Professor, Dept of Physiology, BGS GIMS, Bangalore, Karnataka
2Assistant Professor, Dept of Physiology, Sree Gokulam Medical College and Research Foundation, Thiruvananthapuram, Kerala
3Professor and HOD, Dept of Physiology, Father Mullers Medical College, Mangalore, Karnataka
*Corresponding author: Dr Anjusha I.B, Assistant Professor, Department of Physiology, BGS Global Institute of Medical Sciences, #67, BGS Health & Education City, Uttarahalli Road, Kengeri, Bangalore South - 560060, Karnataka, India, Phone no: 09449066022, E-mail - anjusha.ajai@gmail.com
Online published on 19 June, 2015.
Studies on cardiovascular changes during breath-hold diving at various depths have shown that there is significant reduction in heart rate. A decrease in cardiac output is a known response during immersion, while a coexisting bradycardia may partly contribute to a fall in cardiac output. But the contribution of changes in end diastolic volume, if any have received lesser attention. Hence, this study was aimed at filling this lacuna by measuring changes in end diastolic volume during immersion of face in water using echocardiography.
To observe the changes in the following parameters during breath-hold face immersion in water using Lead 11 ECG and 2D Echo
Heart rate (HR)
Left Ventricular End Diastolic Volume (LVEDV)
Left Ventricular End Systolic Volume (LVESV)
Left Ventricular Stroke Volume (LVSV)
15 healthy male swimmers of the age group 20 to 35 years, who swim at least two hours per week were selected for the study.
There was a statistically significant reduction in HR, as well as a statistically significant increase in LVEDV and LVESV. The increase in LVSV was not of statistical significance.
Bradycardia is a common feature observed in both actual diving and breath-hold face immersion in water. An increase in the LVEDV can be attributed to the coexistent bradycardia. A slight increase in the LVSV observed in this study is contrary to our expectation, since the LVESV
showed a significant increase. This would mean, a reduction in myocardial contractility might have contributed to an increase in the LVESV. Earlier studies have shown that stimulation of trigeminal receptors on the face during diving can influence the vasomotor centre and stimulate parasympathetic influence on the heart. This explains both, the bradycardia and an increase in LVESV observed in the present study.
Cardiac function, immersion of face in water, End Diastolic volume, End Systolic volume
